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When-X · Coach map · Not a prescription

When RBC magnesium is low, or symptoms plus a useless serum

Serum magnesium can look fine while tissue is not. The owner's rule is to read RBC magnesium. Cramps, poor sleep, or a GLP-1 / low-carb week do not replace the lab.

Read this first

  • Coach, not doctor. Aaron Cuha is a coach, not a doctor. No clinical credential is claimed for him, or for these pages. A number on a panel is a conversation starter with a clinician, not a DIY diagnosis. Nothing here is a prescription, a protocol, or a reason to start or stop a medicine. Educational use only. This database summarizes published research and is not medical advice. Where a dose appears it is a record of what a trial or clinic ran, or what people describe doing, with its source attached. Nothing here is a recommendation for personal use.
  • Affiliate disclosure. Knowledge stays free. Every page, every guide and every tool is free to read and stays free. Lab-panel affiliate links, when they exist, live on /bloodwork/partners and print what is earned on the row, or that nothing is earned today. This glossary does not sell panels. The Archive does not order labs.
  • Three lab stories stay separate. /bloodwork is the human panel. /testing and /prices/labs are peptide certificate chemistry. /supplements/quality is what is in the bottle.

The coach gate

Check eGFR first. Magnesium is not a casual bottle when the kidneys are not clearing it. Diuretics and some reflux medicines belong in the same conversation.

What this does not mean

It does not mean magnesium threonate is a brain drug. It does not mean glycinate is proven for sleep. The blood-pressure effect is about 2 mmHg in a 34-trial meta-analysis. Real and small.

Markers to put on the requisition

Candidate supplements, not orders

What people typically order

Ask for RBC magnesium and a BMP with eGFR. Serum magnesium on the BMP is context. An 'electrolyte' powder is not a lab.

Bloodwork partners · Supplement brand partners

Stopping rule

Retest at about ninety days. If RBC magnesium did not move, stop the bottle or change the form with the clinician, and check whether the label was quoting elemental magnesium.